A today's widely used system in crowd computing field permits a plurality of request sources to make a process request to a database. A system of the type receiving a process request to a common server from a plurality of clients as request sources includes a plurality of nodes performing the received process request.
However, if the system merely causes the plurality of nodes to perform the plurality of process requests, a progress status of each node is difficult to learn in response to the process request. It is likely that the process requests center on a particular node. A technique of using a forward proxy device for receiving together the process requests from a plurality of clients is available.
The forward proxy device evenly sorts the received process requests among a plurality of nodes in order to lighten workload in each node. The use of the forward proxy device helps learn which node performs a process request issued by a process request source as a client. Replication transparency and location transparency are thus guaranteed (as described in Japanese Laid-Open Patent Publication No. 04-219844).